Rotary core drill



Patented Feb. 1, *1927,*

UISJITEDl 'STATESg y vg 1,515,921 `PMEIW OFFICE@ WALTER NjmnoMrsoN, or TAFT, cALironNIA, AssreNOR fro STANDARD OIL COM; PANY, OF sAN FRANCISCO, CALIFORNIA, A CoRroaArIoN or CALIFORNIA.

ROTARY CORR DRILL. y

Application filed July 28, 1925. Serial No. 46,630.

Thisinvention relates to core drills for forming and removing a core from a hole being drilled in the earth, and is more particularly directed to a core drill of the rotary type adapted to secure a core from the formation in a' single'piece so that the stratum in the core will remain in propery position in relation to the adjacent strata.

Core barrels as now used are fory the purpose of ascertaining the nature or composition of underground formations and are of suoli construction andmanner ofuse that the core taken will not indicatejtheL direction of tip andstrike of the formation; as these prior core drills have no provision forvpreventing or determining the amount of rotation of the core during core cuttingiand removing operation. v

In many prior types of core drill,1core retainers have been employed which have vertical axial bores in the lower ends thereof which vertical bores, being of the same diameter as the central aperture between the cutting teeth, causek the core to bind at this point so that cores taken by these core drills are usually fractured in several places and each section of the core rotated through a diferent angle. It will be obvious that such a core would not show, or even indicate,

fthe true relation of angles of dip and strike ofthe strata in the core.

An object of this invention is to produce a core'drill adapted for taking Scores by cutting the same from the formation in a single piece so that each stratum in the core willy remain in proper relation to the adjacentA strata so that the angles or dip and strike of the strata in the core may be determined when the core is raised to the `surface at which time the amount ofrotation ofthe drill pipe as it is withdrawn' from 'the well is determined so that the core can be oriented to the position corresponding to its original position in the well.v 4 f' Another object of this invention is to provide a core drill by means of which a core may be taken from underground formations and in which core drill means are provided for eliminating the source of friction between the core `and the core drill so that onv n ti-on corresponding to its original position in the well.

Another object of this invention is to provide a 'core drill in which there' is provided an inner barrel and means within the core drill by which the inner core-receiving barrel may be actuated tocut or break loose the core when the same has beentaken lfrom the underground formation. f f

Another object of this invention isr to pro*y y videa' core drill in which kmeans arel pro.-y vided for cutting loose the core from the formation so that itis unnecessary to burn inthe hole first as is now'coinmon practice.

Other objects and advantages of this invention will be apparent from the following detailed description of a preferred embodiment thereofy as illustrated in the accompanyingdrawings.

In the, drawings: Fig. 1 is a vertical central section ofy an assembled core drill embodying thisin'ven-v tion. l l l Fig. 2 is yan enlarged fragmental vertical section of the core drill taken at 90 from Fig; 1,' 4illustrating the jar construction with female threads 2 to receive male threads n on a core cutting head or body 3, `and male threads on the tool joint 4 by means of which the. same is connected to the string of drill pipe. Loosely supported within the outer barrel l at the lower end thereof is a corereceiving shell 5 which is constructed of thin metal and whichis slotted at its lower end as at 6, and rwhich core-receiving shell 5 has a circumferential recess 6a at the l lower end vthereof to kaid in the crimping of the said shell as will hereinafter appear. The circumferential recess 6a provides a space 6bv which communicates with the longitudinal slots 6 formed in the lowerend of the core' receiving shell 5. `Secured within plate? which' guide plate 7 has an interior bore 8 through which af. stem 9 project-s. A

preferred embodin'iient of `this in` theybarrel l at ak pointy abovey the core-receiving barrel 5k is a yguide.

plurali-ty otports 10 are formed in the plate 7 so. as tofpermit the :tree passage 4of `flushing fluid into the space between the inner barrel 5 and the outer barrel 1. The .stem 9 is secured -to a head vmember 11 which head member' l11 is rigidly secured tothe upper end of the core-receiving barrel 5 and-which head member 11 has a plurality ordongitudinal flushing fluid ports -12 formed therein which are for the purpose of establishing communication 'from the spa-ce -between the barrels 1-afnd -5`and lthe' interior-'ot` the vbarrelft). The ports 12 communicate'with' a yentically extending lport 13: in wli'i'chzport 13ia`ballcheck Valve 14 is-inounted. -Mounted within the upper vendxot"thebarrel 1 and screwthreaded :tothe o'ol joint L isy a sleeve 15-1Which n'sleeve 15has a plurality fot"A ports :16;v formed :therein through- Awhich the flushingluid' isf'permitted to. pass troiii-`tlie interior/bore. 17 ofV the -tool .jointet fand which sleeve lflikewiseY has a plurality: ot ports '18 formedgin 'its' lower tend to perm-it the discharge ofthe .flushing Huid' trom `within thesleeve 15. A mandrel 19 is screw 'threaded to the sleeve 15 as illustrated'atxQOjrandeX- tends upwardly approximately halt' of the length -lothe 'sleeve; 15. :A v*jar head"21l is guided withinthe mandrel 19: and ris yieldably supported within the sleeve 15 by means 'of-afsp1ing;22, which spring22 vencircles the mandrel a9 fand engages the lower end'ot the sleeve 15 .and engages ati its Vupper end a Washer 23 whichi iszmaintainedin position by means offa nut -2ll`whi`ch isfscrew threaded to the -headx 21.

Screw threaded to the lower end nt-'thc r0d;:22'fand|` yieldahly vsupported '-thereby,` is a 'heavy weiglit25whichlheavy weight'25 yis adapted to engage the upper end ot the inandrelor 'stem 19 when thecore ydrill is raised hythewluid 4string and 'dropped quickly. This -fdropping ofthe "core drill causes.V the weight- 25" tto strike lthe -ste1n\9, likewise causing; the innerlbarrel 5` -to be jarred or hammered fdownward through fthe A-co're drill hea d 3 which criimps'theiflower slottedend'iot'the inner-f barrel 5 as wifll hereinafter :bendescribed.

:The inner Ibore otvthe core;V head is of reduced =diameter at the "lower cutting end 26 Land is taperedr-rearwardly from: this reducedzportion as illuseratedat27 toy a diameter fequaltojehe outer Sdianieter yofthe corereceiving barrel V5. The `llower vendv ot lthe core-receivingbarrel 5 therefore rest-s Vupon the taperedsection 27 of the coref'driall. head. Upon the core-receiving barrel "5 lbeing forced downward by the 1 hammerf25 striking the "stem 9,'the' flower slotted end of the core-receiving barrel 5l is crimped Orbent inwardalong the fslotted portion 27 ofthe core drill diea'd `or fbitc, which vcrimping of the' lower 'end .of the ferire-receiving barrel 5. results 'in'w the cuttingfl'oosenotthe core from the formation. The lcore :drill head 3 -may be of 'any desired or preferred construction and is herein illustrated as including a plurality of outwardly diverging water ports 2S adapted to direct iiushi'ngfluid against 'the walls ot the hole being cored and as-i-ncluding a plurality ot radially opposed cutters 29 and upon the lower end ot'whichcore drill-head 3 a cutting surface 30 is formed. The head member 11 is removably secured `t-o thecore-receivingbarrel 5 `b iffmeans of afpair ot-'screw studs Bl'which are VAscrew threaded Linto the head'niember 1f-1 when the same is inserted within 4the upper end or the core-'receiving barrel 5 and/'which studs project outward from `the head 11 into the` L-slot 'formed in It-he upper I'end of the core-receiving barrel `5.

The operation or' this core'lbarr'el is as follows The core barrel yis rotatedupon the torination until :the'desired llength ot core=has been cut. The drillk pipe'andattachedi Acore barrel are thenraised a few `incheswand then dropped upon the bottom 'ot 'the hole,l much after the manner'o't spudding7 a well. The jar which Yoccurs when the'cutting head '3 strikes the bottom ot' the'wellcausesthc weight 25 to descend, ycompressing 'the spring 22'and striking ythedriring pinf'9 'la' sharp blow. `This may be Vdone Vone or more vtimes as may be necessary. The driving `ipin '-9 lbeing attached to the core retainer shell '5 'by means or' the driving head 11, forces the `core retainer shell 5 down` intothe 'downwardly 'reducedrtapered vborer 27 of 'the cutting head 3 causingsaid core retainershell 5 to become crimped vinwardly against they core which may be `partially rractured by Vthisoperation. The core barrel is then pulled:upward'ca-using the core to be completely severed 'from t-he Vsurroundingtorina'tioi'i rat' the pointv ot crimping. rlhiscrinunin the bottom ofthe core retainer shell'also aids in preventing the escape of the corewhile the core or barrel being drawn to the sur-face.

It will readily he seen from the toreg'oing description that, after the core has been severed from :the surroinrding formation. there can be no rotation of the coreiwith respect 'to the core barrel or'dr'ill pipe for the reason that the core Iis gripped tightly by the crimped core retainer shell which is itselt' wedged tightly into the tapered bore ot the cutting head f3. The cutting Ahead outer core barrel 1? and coupling 4 arcall rigidly secured to the tubing string (not shown). Thus any rotation fot'the Vcore which may occur while drawingV the core harrel to the surface will necessarily vbe due to'rotation of the entire tool string. vSuch rotation may be noted at the ttop of vthefwell by marking the drill pipe in `some suitable manner and observing the famount of rotation that has occurred. jThe recovered core may then be oriented to correspond with its original position in the well and the direction of the dip and strike of the formations in the core will be in the same direction as the direction of the dip and strike of the subterranean forlnations from which the core was cut.

IIaving fully described ar preferred embodiment of my invention, it is to be understood that I do not wish to be limited to the exact details herein set forth which may, obviously, be varied in detail ywithout departing from ythe spirit of my invention as set forth in the appended claims.

I claim:

l. A rotary core barrel comprising an outer barrel carrying a rcutting head on the lower end thereof, said cutting head having a' downwardly reduced tapered bore, an inner core retaining shell vertically movable within said outer barrel, and means for driving said inner shell downwardly into the taper ed bore of said cutting head, said driving means comprising a weighted plunger, and spring means mounted within the outer barrel above the said shell for yieldably suspending the weighted plunger above said iuner core retaining shell.

2. A rotary core barrel comprising an outer barrel, a cutting head attached thereto and having an axial bore, cutting teeth diss posed around said axial bore adapted to cut a core of smaller diameterthan the said axial bore, an inner core retaining shell, a` weighted plunger, spring means mounted within the said outer barrel and attached to the said weighted plunger so that when the said core barrel is dropped the vsaid spring means is depressed to permit the weighted plunger to strike the endv of the said shell and move the f same into ka tapered section of the cutting head to crimp the lower end thereof.

3. A core barrel comprising an outer core cutting barrel having a downwardly revducedfaxial bore therethrough, an inner core er core barrel, a cutting head secured to thev said core barrel at the lower end thereof, a core retaining shell mounted in the outer core barrel, a weighted plunger mounted in the core barrel abovethe `upper end of the said shell, spring means mounted in position within the outer core barrel and secured to the said plungerr and adapted to yieldably support the same, and' means at they lower end of the said shell for crimping the same when the said core barrel isdropped to cause the said plunger' to engage the said shell to move the same longitudinally of the said outer core barrel. f

In a rotary core barrel, the combination of an outer core barrel, a core retaining shell mounted within the said outer core barrel, a weighted plunger, spring means yieldably supporting the said plunger, means lfor supporting the said spring means, said latter means having a fluid passage therein, and means at the lower end of the said core drill for crimping the end thereof when the said core barrel is dropped to move the said plunger against the spring pressure to cause the same'to engage the said shell to move the same longitudinally within the said barrel.

6. In a rotary core barrel, the combination of an outer barrel, a core retaining shell slidably mounted within the said outer barrel, a weighted plunger, spring means for yieldably supporting the plunger within the barrel, means for mounting the said spring means within thesaid barrel, said means having a fluid passage therethrough, a head member secured at the upper end of the said shell and having a valvedkfluid passage formed therein, and a stem secured to the said head and adapted to be engaged by the plunger. s

7. In a rotary core barrel, the combination of an outer core barrel, a core retaining shell mounted within the outer core barrel, a sleeve secured to the said core barrel at its upper end, a mandrel passing throughthe said sleeve at its lower end, a weightedplunger secured to the lower end of the said mandrel, a spring mounted on'the said mandrel for yieldably supporting the said weighted plunger above the upper end of the said shell, and means for crimping the lower end of the said shell when the said plunger strikes the upper end thereof.

Signed at Bakersfield, California, this 17th day of Julyl 1925. f

WALTER N. THoMPsoN. i 

